I. Field of the Invention
The present invention relates to a telescopic extension for an electric household appliance.
II. Related Art and Other Considerations
EP-B1-0 520 534 discloses a telescopic extension for a vacuum cleaner, comprising an inner tube and an outer tube sealingly slidable one inside the other, a sleeve, a means for constraining the inner tube and outer tube, a thrust slider and an actuating pushbutton.
The inner tube is provided with a row of recesses having a predefined shape and the outer tube is provided with an end tubular portion with a flared shape which is formed as one piece therewith and inside which the sleeve is fastened.
The constraining means consists of a cylinder piece integral with a plate provided with a pin. By means of the pin and the plate, the cylinder piece is rotatably supported in a hollow seat of the sleeve. The seat has, formed in it, a slit by means of which the cylinder piece is able to engage with a recess of the inner tube and disengage from the recess.
In this telescopic extension, the thrust slider is operationally connected to the actuating pushbutton, is slidably supported inside the seat of the sleeve and is subject to the action of resilient means.
The resilient means cause the thrust slider to engage with the plate integral with the cylinder piece to force the latter into the recess of the inner tube and lock the inner tube inside the outer tube. As a result, the extension assumes a predefined length.
In order to adjust the length of the extension, the actuating pushbutton is pushed manually against the action of the resilient means so that the thrust slider is able to disengage from the plate and leave the cylinder piece free to come out of the recess of the inner tube, releasing the inner tube from the outer tube. By means of sliding of the inner tube inside the outer tube, the extension assumes the desired length.
In order to assemble the extension, the sleeve is fitted onto the inner tube and the constraining means, the slider/pushbutton assembly and the resilient means are pre-mounted in the hollow seat of the sleeve. Then, the inner tube is mounted inside the outer tube and the sleeve is inserted into the end tubular portion, centred with respect thereto, passing the slider/pushbutton assembly through an end opening of the outer tube.
The object of the present invention is to improve the abovementioned extension, reducing the number of components and making assembly easier.